1. Lab 6
Introduction to grammars
Vectors in C++
Lab Exercise

2. What is a grammar A grammar is a 4-tuple (N, T, Π, S)
 A terminal symbol is one that cannot be broken down further
A non-terminal symbol is a symbol that can be reduced further by the production rules
N∩T
The language of a grammar is the set of strings it generates.
S → NP VP
NP → the N
VP → V NP
V → sings | eats
N → cat | song | canary

3. Terminals: the, sing, eat, cat, canary, song
Non-terminals: S, NP, VP, V, N
Start-Symbol: S
Some strings: “the canary sings the song”
“the song eats the cat”

4. Recursive vs Non-Recursive
A grammar is called a recursive grammar if it contains production rules that are recursive, expanding a non-terminal according to these rules can eventually lead to a string that includes the same non- terminal again.
Word -> A B
A -> a
A -> b
A -> B
B -> c
B -> d

5. Vectors
It is a container that can store elements, but its size can change dynamically
Vector elements are placed in contiguous storage so that they can be accessed and traversed using iterators.
vector<dataType> vectorName;
Push_back(),pop_back(),size(),erase(),swap(),insert()…..

6. Lab 6